1. Field of the Invention
The invention relates to an enhanced arrangement for disengaging and separating two mated components, such as two mated parallel printed circuit boards of a computer.
2. Background Information
Computer systems typically include a number of printed circuit boards that are electrically coupled together. One way to accomplish this is to use electrical cables to electrically join respective printed circuit boards. The cables are typically connected to plug connections disposed on the surface of the respective printed circuit boards. The cables allow various electrical signals to be transmitted from one printed circuit board to the other printed circuit board, for example, so that various electronic components on one printed circuit board can communicate with electronic components on the other printed circuit board.
One problem with the cabling scheme is that the distance that the electrical signals must travel may be relatively far. Since the distance the signals must travel may be great, the associated signal response time may be slow. To reduce this distance, the respective printed circuit boards can be directly connected to one another. For example, one printed circuit board may be provided with a slot in which another printed circuit board may be inserted. Using this arrangement, the two boards are perpendicular to each other when xe2x80x9cmatedxe2x80x9d together. Beyond the distance advantage described above, this arrangement has the further advantage of easy insertion and removal of one card from the other.
While this perpendicular arrangement does have certain advantages, various computer system constraints limit greatly the extent to which this arrangement can be used.
Thus, it is also known to arrange the two printed circuit boards over each other. In this configuration, one of the printed circuit boards is provided, for example, with a female type plug on its surface, and the other printed circuit board is provided with a male type plug on its surface. The female type plug and the male type plug are typically aligned with each other, so that when the one printed circuit board is disposed over the other printed circuit board, the respective plugs can be electrically engaged with each other, thus electrically coupling the printed circuit boards to each other.
This arrangement can be easily assembled, simply by pressing the boards together in a region of the plugs. However, the disassembly of the arrangement can cause the printed circuit boards and/or their respective plugs to become damaged. That is, to disassemble this arrangement, it is conventional to grip the edges of the respective printed circuit boards, in an attempt to pull them apart and disengage their respective plugs. However, one problem with this approach is that this action will cause the boards to flex relative to their point(s) of attachment, i.e., at the respective plugs. Moreover, the greater the distance from the plugs to the edge of the printed circuit board(s) that is being grasped, the greater the flexing of the printed circuit board(s). While printed circuit boards can withstand a slight flexing without permanent damage, if the flexing becomes too great, the printed circuit board may crack, and/or the respective wirings of the printed circuit board may shear, rendering the printed circuit board(s) inoperative. Moreover, the flexing of the printed circuit boards may cause electronic components to pop off from the surface of the flexed printed circuit board, rendering the printed circuit board defective.
Moreover, this method of disengaging and separating the printed circuit boards has the problem of asymmetrically applying the separation force, i.e., only on one side of the plugs. The applied force may therefore cause the plugs to rotate, which may cause the respective conductive pins of the plugs to bend and/or break.
Thus, there is a need for an arrangement that will allow two superposed, mated printed circuit boards to be easily disengaged and separated from each other without flexing the respective printed circuit boards.
Further, there is a need for an arrangement that will allow two superposed, mated printed circuit boards to be disengaged and separated from each other without asymmetrically applying a force relative to a plug or other connector that electrically couples the two printed circuit boards together.
It is, therefore, a principle object of this invention to provide an enhanced arrangement for disengaging and separating two mated components.
It is another object of the invention to provide an enhanced arrangement for disengaging and separating two mated components that solves the above mentioned problems.
These and other objects of the present invention are accomplished by the enhanced arrangement for disengaging and separating two mated components disclosed herein.
In an exemplary aspect of the invention, a disengagement mechanism is used to separate two superposed printed circuit boards from each other, by causing their respective electrical connectors to disengage. This advantageously allows the printed circuit boards to be easily separated, without damaging their respective electrical connectors or other components thereof.
In another exemplary aspect of the invention, a stiffener panel is provided with grooved recesses provided on opposite sides of a hole therein, so as to receive various components of the disengagement mechanism. This allows the components of the disengagement mechanism to be nested within the stiffener panel, thus advantageously minimizing wasted space.
In an exemplary aspect of the invention, the disengagement mechanism includes two cam assemblies. Each cam assembly includes an elliptically-shaped cam disposed to rotate within a respective grooved recess. Each cam assembly further includes a pair of pins projecting out from opposite sides of the respective cam, and being disposed within a respective pin-accommodating portion. The pins are disposed offset toward one end of the respective cam, so that another portion of the cam that is disposed furthest away from an axis of rotation, which extends through the respective pins of the cam assembly, will define a high point of the cam. As such, when the cam assembly is rotated in a first direction about the axis of rotation, the high point of the cam will rotate to a position that projects above a surface of the stiffener panel (i.e., above an upper edge of a lip of the panel). Further, when the cam assembly is rotated in an opposite, second direction about the axis of rotation, the high point of the cam will rotate to a position that is level with or below the surface of the stiffener panel. This configuration allows the disengagement mechanism to be easily utilized with a planar sandwich arrangement, for separating the printed circuit boards and disengaging their respective mating components.
In order to retain the pins of the cam assembly within the respective pin-accommodating portions, a plurality of cover plates are provided. In an exemplary aspect of the invention, the cover plates are disposed directly over the respective cam assemblies and secured to the stiffener panel, using threaded fasteners, for example. Moreover, each cover plate has a hole formed therethrough, through which the high point of the cam may project when the cam is rotated about the axis of rotation. The cover plates advantageously allow the cam assemblies to be adapted for use with a stiffener panel.
In order to automatically rotate the cams in the second direction, so as to retract the high point of the cam level with or below the surface of the stiffener panel, each cam assembly is advantageously provided with a torsional helical spring. Preferably, each respective torsional helical spring is disposed about a respective pin. Moreover, each cam can be provided with a groove that surrounds the respective pin, in which the torsional helical spring can be at least partially accommodated.
As the cam is manually rotated against a force of the spring, for example, in the first direction so that the high point of the cam projects above the surface of the stiffener panel, the spring will exert a torque in the second direction. Thus, the spring advantageously allows the cam to be automatically rotated in the second direction, and fully retracts the mechanism into the stiffener panel.
In a further aspect of the invention, and in order to manually rotate the cam in the first direction, each cam is connected to a handle. For example, the high point of each cam can be connected with a single U-shaped handle, which when pulled, advantageously causes both cam assemblies to simultaneously rotate in the first direction.
In an exemplary aspect of the invention, the handle projects outward toward an edge of the stiffener panel. The outer peripheral lip of the stiffener panel can then be removed in a region of the handle, so as to allow access to the handle. Moreover, the handle can also be tailored to project beyond the outer edge of the stiffener panel. These features all allow easy access to the handle, so that it may be readily grasped by a user seeking to separate the printed circuit boards.
In use, the user simply pulls on the base of the handle, causing the cams to simultaneously rotate in the first direction, and moving the high points of the cams above the surface of the stiffener panel. Further, as the handle is pulled, the high points of the cams will simultaneously contact the lower surface of the upper printed circuit board, and subsequently begin urging the upper printed circuit board away from the stiffener panel and lower printed circuit board. Because of the symmetrical application of force on opposite sides of the electrical connectors, and due to the proximity of the cam assemblies to the connectors, the mating components of the connectors will smoothly disengage, without causing damage to the connectors or printed circuit boards.
After the printed circuit boards are fully separated, the handle is released, allowing the springs to automatically rotate the respective cams in the second direction. This advantageously causes the high points of the cams, corresponding holes, and ends of the handle to automatically move to a level even with or below the surface of the stiffener panel.
Moreover, the size and shape of the cam can be modified to meet the needs of the user. By increasing the distance from the high point of the cam to the axis of rotation, the mechanical advantage resulting from the cam will be increased. Thus, the cam assembly is scaleable and modifiable to other applications requiring greater (or lesser) disengagement forces.